It is now possible to compile MySQL 5.6 using OpenSSL 1.1.1, enabling compilation support for MySQL 5.6 against OpenSSL even when OpenSSL 1.0.2 reaches End of Life status at the end of 2019.

In addition, MySQL 5.6 now supports TLSv1.1 and TLSv1.2 protocols for encrypted connections. This applies to MySQL Server, MySQL clients such as mysql and mysqldump, and master/slave replication. Previously, MySQL 5.6 supported only TLSv1, so TLSv1.1/TLSv1.2 support enables use of more secure TLS protocols. It also enables connecting from MySQL 5.6 clients and replication slaves to MySQL 5.7 and higher servers that have TLSv1 disabled, which previously was not possible. It also means that MySQL 5.7 and higher clients that do not want to use TLSv1 can connect to MySQL 5.6 servers.

All MySQL 5.6 builds now use OpenSSL. MySQL no longer supports using yaSSL as the SSL library, and source distributions no longer include yaSSL.

The WITH_SSL CMake option no longer permits bundled (use yaSSL) as a valid value, and the default option value has changed from bundled to system (use the version of OpenSSL installed on the host system).

The linked OpenSSL library for MySQL Server has been updated to version 1.1.1c. Issues fixed in the new OpenSSL version are described at https://www.openssl.org/news/cl111.txt and https://www.openssl.org/news/vulnerabilities.html. (Bug #29868818)

Improper locking during storage engine initialization could cause a server exit. (Bug #29782379)

VS2019 produced compilation errors with debug compilation selected due to use of the /ZI flag. Now /Z7 is used instead. (Bug #29691691, Bug #95125)

For MySQL Community Edition, the cipher order specified by the client was used in preference to the order on the server side, unless the server was configured with an explicit ssl_cipher order. (Bug #26882825)

Password masking was incomplete for SHOW PROCESSLIST and some INFORMATION_SCHEMA and Performance Schema tables. (Bug #20712046)

The -DWITH_EXAMPLE_STORAGE_ENGINE=1 CMake option was ignored but should not have been. If -DWITH_EXAMPLE_STORAGE_ENGINE=0 is given, the EXAMPLE storage engine is built as a plugin. (Bug #70859, Bug #17772560, Bug #30133062)

References: See also: Bug #18324650.